The present invention relates to load control and switching circuits and, more particularly, to novel remotely controllable circuits for controlling the presence and amplitude of power consumed by a load.
It is desirable to actuate each of a plurality of power-consuming loads, and to set the power-consumption level thereof, from a central control facility. Switching and control of the power-consuming loads are advantageously commanded both manually and on a programmed basis. Further, a system allowing such load activation and level control will advantageously provide a common transmission medium between the central facility and all of the plurality of remote locations, to reduce cost of the system. For example, all of the lights in a residence may be controlled by a central facility allowing the light level in each room of the residence to be adjusted on a time-of-day schedule, while further providing for manual intervention from specific locations (such as at the house entrance or in the master bedroom) for controlling all light sources within that residence.
Heretofore, individual wiring, between remote switches and each load to be energized and level controlled, was commonly utilized. More recently, centrally-programmable load switching systems have been utilized for the purpose of enabling and disabling current flow through a particular load; active control of the power consumption of a single load has not been hitherto possible in programmable, central-control systems. Accordingly, remotely load control and switching circuits for use in such a system, are highly desirable.